The athlete's perception on the extreme exercise hypothesis

Abstract Background Exercise is known to promote cardiovascular (CV) health, but emerging evidence suggests that high-volume high-intensity exercise may be harmful to the heart. The athlete’s perception on the potential risks of exercise remains to be elucidated. Purpose To assess the athlete’s perception on the extreme exercise hypothesis. Methods Recreational athletes ≥18 years were invited to complete an online questionnaire about their exercise behavior, CV health, and perception towards the risks and benefits of exercise on CV health using a 5-point Likert scale and multiple-choice questions. Responses were dichotomized ((strongly) agree versus neutral or (strongly) disagree) and compared with the McNemar and Cochran’s Q test. Associations between perception scores and age, sex, CV health, and exercise volume were tested with logistic regression analysis. Results 2,881 recreational athletes (54±15 years old, 43% female) participated in this study of whom 1,920 (66%) were healthy, 739 (26%) had CV risk factors and 222 (8%) had CV disease. Participants exercised for 6 3.5-9 hours per week with an exercise volume of 44 28-67 Metabolic Equivalent of Task (MET)-hours/week. The perceived risks of moderate-intensity exercise increased with the frequency of training sessions, with 2% of participants agreeing that 1 training session per week can be harmful for CV health to 6% at ≥4 training sessions per week (p0.001, Figure 1A). The perceived risks were higher for high- versus moderate-intensity exercise (p0.001), independent of the number of training sessions per week. For high-intensity exercise, the perceived risk increased from 6% at 1 training session per week to 9% at 2-3 sessions and even 30% at ≥4 sessions per week (p0.001, Figure 1B). The perceived CV risks at ≥4 high-intensity training sessions per week were higher in males versus females (ORadjusted: 1.19; 95% CI: 1.00-1.41; p=0.047) and higher in younger (≤45 years) versus middle-aged (ORadjusted: 1.34; 95% CI: 1.08-1.66; p=0.008) and older athletes (65 years, ORadjusted: 1.61; 95% CI: 1.29-2.01; p0.001), whereas CV health status and training volume did not impact our findings. Furthermore, 1 in 3 athletes (34%) reported to worry at least rarely that exercise could be harmful for their heart, mostly linked to an elevated risk of myocardial infarction (13%), arrhythmias (10%), and sudden death (9%). Key contributors of these concerns were media reports about exercise-related cardiac events (12%), a cardiac event in a close relative (9%), and warnings from relatives (8%). Of all participants, 7% reduced their exercise intensity or frequency because of these worries. Conclusion Higher exercise frequencies and intensities were perceived as more harmful for CV health, especially by younger male athletes. 1 in 3 athletes worried at least rarely about the potential cardiac health risks of exercise, primarily triggered by media reports and cardiac events in close relatives.For image description, please refer to the figure legend and surrounding text.